Textile drafting mechanism



My 3o, 1944.

B. C. SHAW TEXTILE DRAFTING MECHANISM Filed Feb. 26, 1942 o s o will iii e Q w b" d all? G E 9 Pw E 2 Sheets-Sheet 1 l *454 V. J l

Maty 30,1944. B. Cj SHAWl y2,350,254

' TEXTILE DRAFTING( MECHANISM v Filed Feb. 26, 1942 2 Sheets-Sheet 2 Patented May 30, 1944 TEXTILE DRAFTING MECHANIS Benjamin C. Shaw, Saco, Maine, assignor to Saco- LowellAShops, Boston, Mass., a corpcrationof Maine applicati@ February 26, 1942, serial No. 432,417

12 claims. (cl. 19-140) 'This invention relates to drafting mechanisms and is more especially concerned with the clearers for the drawing rolls or equivalent drawing elements.

The prior art clearers in common use are of two types, namely, anat clearer and a revolving clearer. The at clearer, as its name implies, has an approximately iiat surface supported in contact with several rolls or roll sections, and the clearer surface consists of a napped fabric or some material of that general nature adapted to clean the lint and fly off the drawing rolls with which it cooperates. The chief disadvantage of a clearer of this type is its relatively small storage capacity for the waste that it accumulates. Because of this fact, its capacity is exhausted after a relatively short period of operation, and any excess of waste thereafter delivered to it is Very likely to drop 01T and eventually to get into the fiber being processed and thus produces a lump in the yarn. This relatively limited storage capacity therefore necessitates frequent removal and cleaning of the clearer itself.

Revolving clearers have a considerably larger storage capacity for waste than do at clearers, but since they run in contact with and are revolved by the rolls which they are supposed to keep clean, they do not exert as effective a cleaning or polishing action on the drafting rolls as do the flat clearers. A further objection to revolving clearers is the fact that the lint and fly which they remove from a drawing roll is not attached rmly to the surface of the clearer, with the result that parts of the accumulated waste may drop back into the machine if, for any reason, the action of the clearer becomes erratic.

The defects above mentioned have long been recognized and are well known, and many attempts have been made to devise a clearer in lwhich the advantages of the two types above mentioned would be combined and the disadvan- 'tages of both would be eliminated. So far as -I am aware, however, none cf these attempts has proved successful. The cone type of clearer is one example of such attempts, and a serious objection to it and to many of the others has been that they. work 4the accumulation of lint and `ily which they have removed from the drawing roll into small rolls, often referred to as rat to devise a thoroughly practical solution for the old problem of providing a clearer having the -advantages of the old types but avoiding their disadvantages.

The nature of the invention will be readil understood from the following description when read in connection with the accompanying drawings, and the novel featureswill be particularly pointed out in the appended claims.

In the drawings,

Figure 1 is a plan View of the front drawing roll of a spinning or roving frame and parts adjacent thereto, showing the machine equipped with a clearer roll embodying this invention;

Fig. 2 is a'front elevation, partly in section, of the clearer roll shown in Fig. 1; and

Fig. 3 is a vertical, transverse, sectional'view through a drawing mechanism for a spinning frame showing it equipped with a clearer roll like that illustrated in Figs. 1 and 2.

Referring'rst to Fig. 3, the machine there lshown comprises front, middle and rear bottom rolls 2, 3 and 4, respectively, and corresponding upper or top rolls 5, 6 and 'l running in contact with and driven by the respective bottom rolls just mentioned. The particular number and arrangement of rolls employedis immaterial so far as this invention is concerned. In practically all of these drawing mechanisms the upper `front roll collects considerably more fly than do 'any of the other Vrolls and the cleaning problem, therefore, is more troublesome at this point-than at any other in the machine. Also, it is customary in these mechanisms to mount a single clearer roll in contact with` three or four drawing rolls of the top front line. The present invention is shown in the drawings as embodied in a clearer roll, indicated in general at 8, and providedl with six cleaning sections a, each of generally cylindrical form, and adapted to run in contact with the fiber engaging surfaces of three of the top rolls 5, it being understood that in accordance with the usual practice each top roll has two bosses covered with leather or some other suitable cushioning material. i

The: fundamental difference. between applicants clearer roll and those heretofore used is Aright angles to the. 30 plane of the rolls themselves intersects the corresponding plane of the line of top rolls at an acute angle having a mag- A:the top rolls .While a smaller: angle reduces eifectivenessof the cleaning action.

It is important thatI such .a roll be driveny .tends to produce cigarettes Aor"rat.tails;

nitude, say, of from 1 to 3, the line of intersection of said planes crossing the axis of the clearer roll at about the middle of the length of the latter.

The body of the clearer roll may consist of a steel rod, machined to approximately the form shown, or, more preferably, of a steel rod 8' on which as eries of wood bosses 8f' is secured. In either event 'the bosses are covered With clearer fabric and they run in engagement with the respective bosses of the top front line rolls. At its opposite ends the clearer roll has two gudgeons 9 and IU resting in slots formed-in two small brackets I2 and i3 which are secured to the upper surfaces of adjacent roll `stands' by screw and slot connections so that they canI be adjusted forward and backward.

It Will be observed that the geometry of this angular relationship between the clearer roll and the top rolls on which it works, requires that f each clearer section be slightly larger at one end Vthan the other, and that the interveningsurface be slightly concaved. Actually, the degree of such concaving effect required isso slight as to be A'practically negligible. The roll, however, is

`naturally larger in diameter at` its `ends than at the middle, and the machined'surfaces of the bosses are so tapered that homologous elements of the entire series-of rbosses lie in a common arc i4, as shown in Fig. 2.

It will readily be understood that .When such a. clearer roll is revolved by theline of top rolls Von which it rests, each of the cleaningsectio-ns, except those at its ends, will exerta vcombignation of a tangential rrubbing action and a longitudinal rubbingiorl scuing, action on the surfaoegof the top roll With Whichit is in contact.

The =;tangential action is produced by the differ- .ence in surface speeds of the yclearer and the top rolls, while the longitudinalrubbingaction isyproduced by an end thrust component due .to the angle between theaxis of the clearer landthat of the top rolls. The fact that this end thrust .is actively working canV readily be seen by placing the clearer inthe frameas far .to the left of theposition shown in Fig. 1 as possible. f As it beginsto revolve it Will immediately travel to the right as far asthe righthand'bearing will permititto go, and thereafter it-.will'remain in this position. The greater the angle between the rolls the strongerwill be this endA thrust component. The combination of ,these l two yrubbing actions not. only produces a very effective cleaning ofthe topY rolls but it also works the lint andfiy into avery dense felt-like `mass which adheres strong1y vto the `fibrous covers on the clearer bosses but can still angle should be at least 1 and as a ruleishould 1 not go over A larger angle has the disadvantage of obscuring the operators view of the ata constant speed `since'vlirregular operation It is preferabletherefore, tomakethe sections at the opposite ends Vofthe Vroll. sufficiently larger than the .interv.ennig .lsections l sdthat these two described,

end sections will support the entire Weight of the clearer and it will be driven by them. The fact that the intermediate bosses do not bear on their respective top rolls is not important so far as the cleaning action is concerned for the reason that the covers on these bosses are made of a lofty fabric and even if little more than the tips of the bers of these fabric sections wipe the surfaces of the top rolls, that is suicient to keep the latter clean. In this connection it may also be observed that the larger end bosses revolve at a higher surface .speed than the intermediate sections and this fact isl of advantage from a cleaning standpoint becausethe ,latter sections revolve at a slower surface speed than do their respective top rolls.

It should be noted that the gudgeons at the opposite ends of the roll are of different diameters, the right-hand gudgeons l0 being larger than the other, and the slot in the left-hand bracket Al2 is made just wide enoughto receive the smaller gudgeon so that thev clearer must always be placed in the machine in the same way. This is of advantage in ensuringzthat the longitudinalfelting action will always be-in the same direction and thuswill make a smoother yand firmer sheet of waste-than would be produced if the action were reversed by vputting the clearer in first one Way and then in the other. rI'hrust washers are positioned on lthe gudgeons to bear against the respective brackets.

It has been found in practice that a clearer of this type does combine the advantagesI of the two nld forms of clearers above mentioned while avoiding the objectionable features of both.

While the drawings illustrate the invention as `applied only to the front line top rolls,` it

will be understood vthat it A may be used lon f any of the other rolls-desired Within the limits of the machine design, and this applies to bottom rolls as Well as totop rolls. Usually it will be found-more convenient, however, to use a stationary top clearer, suchv as that shown at l5, on the middle and back top rolls. In;the drawings the degree of taper ofthe bosses is somewhat exaggeratedy merely for purposes of illustration.

While I have herein shown and `described `a preferred embodiment ofmy invention, it will be evident that the inventionl may be embodied in somewhat different forms without departing from the spirit or scope thereof.

4I-aving thus .described -my invention, what vI desire to claimas new is:

1.7111- a vdrawing mechanism of the character thel combination with a series of drafting-rollgsections .arranged in axial alignment, of aplearer. roll of generally cylindrical .form but having circumferential cleaning surfaces-tapering from opposite end portions -of the rolltoward an intermediate-,portion of smaller diameterthan said end portions, and means supporting said clearerrollin Contact with said drafting roll sections and in a generally parallel relationship thereto. but with the plane of lits axis intersecting the yplane of the axis of said draftingro-ll sections at an acute angle'of such magnitude as to --produce both tangentialand -v-endwise rubbing actions on said s ceding claim ,1,1 aconstruction.-including means supporting the clearer roll against end thrust in one direction.

4. In a drawing mechanism according to preceding claim 1, a construction in which the supporting means for said clearer roll cooperates therewith to prevent the latter roll from being reversed with reference to the drafting roll sections.

5. In a drawing mechanism according to preceding claim 1, a construction in which the clearer roll comprises a plurality of cleaning sections spaced lengthwise of the roll, and the end sections are suiciently larger in diameter than middle sections to drive the clearer roll substantially to the exclusion of the middle sections.

6. A clearer for drafting rolls comprising a roll having a plurality of cleaning sections to engage corresponding sections of a drawing roll, said clearer roll being smaller in diameter at intermediate cleaning areas than at opposite ends of the roll, homologous elements of said areas lying substantially in a common arc of a circle of relatively large radius.

7. A clearer for drafting rolls comprising a roll having a plurality of cleaning sections to engage corresponding sections of a line of drawing rolls, the end sections of said clearer roll being larger in diameter than intermediate sections said end sections being tapered slightly, with their smaller endstoward the middle of the roll.

8. A clearer for drafting rolls comprising a roll having a series of cleaning sections spaced longitudinally thereof to engage a corresponding series of fiber drafting sections of a line of drawing rolls, said cleaning sections being lar-ger in diameter at opposite ends of the roll than at an intermediate portion thereof, and elements of said sections lying substantially in a common arc of a circle.

9. In a drawing mechanism according to preceding claim 1, a construction in which said means supports said clearer roll for rotation by said drafting roll around a stationary axis.

10. In a drawing mechanism according to preceding claim l, a construction in which said means supports said clearer roll for rotation around a stationary axis by said drafting roll and holds said clearer roll in an axially stationary position.

11. In a drawing mechanism of the character described, the combination with a drafting roll, of a clearer roll of generally -cylindrical form but having circumferential cleaning surfaces tapering from opposite end portions thereof toward an intermediate portion of smaller diameter than said end portions, and means supporting said clearer roll in contact with said drafting roll and in a generally parallel relationship thereto but with the plane of its axis intersecting the plane of the axis of said drafting roll at an acute angle of small magnitude, the line of intersection of said planes passing through said intermediate portion o-f the clearer roll where it is of smaller diameter.

I 12. In a drawing mechanism according to preceding claim 1, a construction in which said clearer roll surfaces are spaced lengthwise of the roll and are shaped to engage approximately the entire lengths of the respective -ber Working portions of said drawing roll sections notwithstanding the angular relationship between said sections and said clearer roll.

BENJAMIN C. SHAW. 

